Complex adaptive optics systems previously used piezoelectric actuators to control the DM figure. For example, a 1500 degree-of-freedom segmented mirror using tubular piezoelectric actuators with a 6 .mu.m stroke was developed by researchers at ThermoTrex. In 1995, FASTTRAC II, a 12 actuator segmented beam combiner for the Multiple Mirror Telescope (MMT), was built using voice coil actuators and capacitor position sensors. In response to astronomical requirements for low-emissivity, large-throw secondary mirrors, prototype adaptive secondary mirrors using 25 voice coil actuators covering a 6-inch square mirror have been built, as well as prototypes with 24-inch diameter deformable mirrors and 60 voice coil actuators. Upgraded MMTs may employ with over 300 actuators. These use fast steering mirrors with voice coil actuators and capacitor position sensors. All of these designs use voice coil actuators with capacitor position sensors to provide feedback to an internal control loop. There remains a need for an actuator which can operate over a longer range and with low maintenance costs.